1. Technical Field
This disclosure relates to antenna system. Particularly, this disclosure relates to phased array antenna systems.
2. Description of the Related Art
An essential component of any wireless communications system is the antenna that transmits and/or receives the electromagnetic signals. One conventional antenna structure, often employed in communications satellites, includes a reflector that has received or transmitted signals “reflected” off it and focused to be collected in one or more feed horns. The reflector and feed horn configuration is typically manipulated to direct or “point” the coverage area of such an antenna. Newer antenna systems may employ phased arrays where an array of discrete antenna elements are used in combination to transmit or receive the desired electromagnetic signal. Such phased array systems can dispense with much of the pointing manipulation typically required with conventional reflectors because the output of the discrete antenna elements of the phased array, through the signal processing, create interference patterns of RF energy that create the desired coverage area and coverage signal strength.
A conventional design approach in developing a phased array antenna (or even a conventional reflector) divides the electrical signal design from the structural design. Thus, the signal design will involve developing the combination of radiating elements, waveguides, and filters in order to achieve the desired coverage and signal strength. Separately, the structural design will be developed to derive the structural configuration for the antenna to support the arrangement of electrical components. This approach can yield results that are less than optimal.
Thus, conventional antenna designs utilize separate structural members to support the antenna. Such conventioanl antenna designs also use individually fabricated feed horns or antenna elements. In conventional antennas, the structural members must be separately fabricated and assembled. This adds extra weight, volume, and fabrication cost. Weight and volume are particularly significant constraints in the design of antenna on spacecraft. For example, lower mass and volume antennas can allow the spacecraft to launch on smaller, less-costly launch vehicles. In addition, the installation of individual horns or antenna elements adds complexity to the dimensional stack up and flow time assembly. Some antenna designs have been developed to alleviate some of these problems.
U.S. Pat. No. 7,046,209, issued May 16, 2006 to McCarville et al. discloses an antenna aperture having electromagnetic radiating elements embedded in structural wall portions of a honeycomb-like core. Independent wall sections each having a plurality electromagnetic radiating elements are formed into the honeycomb-like core. Feed portions of each radiating element form teeth that are copper plated before being assembled onto a back skin panel. Each of the teeth are then generally machined flush with a surface of the back skin to present electrical contact pads which enable electrical coupling to each of the radiating elements by an external antenna electronics board.
However, there is still a need in the art for apparatuses and methods for antenna systems that are structurally efficient, with reduced mass and/or volume. In addition, there is a need for such apparatuses and methods to deliver high performance spacecraft antenna on less expensive launch vehicles. There is also a need for such apparatuses and methods to provide phased array antenna that are cheaper, lighter and more powerful than convention antenna systems. There is particularly a need for such methods and apparatuses in spacecraft applications. These and other needs are met by the present disclosure as detailed hereafter.